Buffing and deburring machine

ABSTRACT

A rotary brush mounted on a power driven spindle which in turn is journaled in a bearing unit that is supported for axial oscillation by a pair of leaf springs, has work fed to it by an endless conveyor located beneath the brush. The bearing unit is axially oscillated by a power driven eccentric.

United States Patent [1 1 1 3,708,817 Rhine et a]. 1451 Jan. 9, 1973[541 BUFFING AND DEBURRING MACHINE 2,153,295 4/1939 Brogden ..15/17 ux[75] Inventors: Wallace R. Rhine, Stillwater; Fred gm? achtman.... bmh2,804,723 9/1957 Sweeney ..51/38 [73] Assignee: Timesavers, Inc.,Minneapolis,

Primary Examiner-Edward L. Robert [22] Filed: March 24, 1971Attorney-Ira Milton Jones 21 Appl. No.: 127,669

[57] ABSTRACT [52] US. Cl ..l5/77, 15/21 R, 51/38 A rotary brush mountedon a power driven spindle [51] Int. Cl. ..A46b 13/04 which in turn isjournaled in a bearing unit that is sup- [58] Field of Search ..l5/2l0,77, 88, 102, 21; ported for axial oscillation bya pair of leafsprings, 51/33 R, 38 has work fed to it by an endless conveyor locatedbeneath the brush. The bearing unit is axially oscil- [56] ReferencesCited lated by a power driven eccentric.

UNITED'STATES PATENTS 9 Claims, 9 Drawing Figures 1,484,766 2/1924Erickson ..l5/77 77 Z 5 1 my :m .Efiw'g [73 7/ PATENTEDJAN 9 I9753.708.817

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BUFFING AND DEBURRING MACHINE This invention relates to brushing anddeburring machines for cleaning, deburring, buffing, finishing andpolishing flat surface of workpieces. While the machine of thisinvention can handle a wide variety of work, it is especially welladapted for the removal of the many burrs that project from the surfacesof printed surface boards after the boards have been drilled for thereception of circuit components.

It is the object of this invention to provide an improved machine ofthis type and, at the same time, reduce its cost.

The machine of this invention comprises a rotary brush or polishing drumdetachably mounted on a horizontal spindle, and an endless belt conveyorbeneath the spindle to carry work through the machine with the topsurface thereof at an elevation to be acted upon by the rotary brush orpolishing drum. A pair of hold-down rolls press the work firmly againstthe conveyor as the work is carried through the machine.

To accommodate work of different thicknesses, the distance between thebrush spindle and the conveyor, and also the spacing of the hold-downrolls above the conveyor, must be adjustable; and to enable brushes orpolishing drums of different diameters to be used, and also tocompensate for any reduction in diameter due to wear, the relativepositions of the spindle as one entity and the conveyor and hold downrolls as a second entity, must be adjustable.

While provision for these necessary adjustments can take various forms,it is a feature of this invention that the brush spindle is notdisturbed in effecting the adjustments. Only the conveyor and thehold-down rolls are adjustably mounted. One adjusting device moves thehold-down rolls up or down with respect to the conveyor, and anotheradjusting means concomitantly moves both the conveyor and the hold-downrolls towards and from the spindle.

By obviating the need for moving the spindle to achieve the neededadjustments, the mounting of the spindle and its drive is greatlysimplified; and, in this connection, a very significant feature of theinvention resides in the particular way in which the mounting of thespindle provides for limited axial oscillation of the rotary brush toassure against the formation of parallel scratch lines or apparentscratch marks on the work surface.

To enable such axial oscillation of the brush, the spindle is journaledin bearings that are fixed in a block which, in turn, is carried by apair of leaf springs. The leaf springs have anchored end portions fixedto the frame of the machine in such a way that the only motion permittedthe bearing block as a consequence of flexure of the springs is in ahorizontal plane.

Another feature of this invention resides in the fact that the machinemay be operated either wet or dry, and in either case those portions ofthe machine that would be deleteriously affected by the conditions inthe zone of action are protected therefrom by the simple expedient oflocating the rotary brush and the work supporting and feeding conveyorat one side of an upright wall that forms part of the main frame of themachine, while all of the mechanism that should be protected is mountedonor located at-the other side of the wall.

example of the embodiment of the invention constructed according to thebest mode so far devised for the practical application of the principlesthereof, and in which:

FIG. 1 is a perspective front view of the machine of this invention;

FIG. 2 is a perspective side view of the machine;

FIG. 3 is a perspective view of the machine taken from substantially thesame angle as in FIG. 2, but with the shrouds or housings removed;

FIG. 4 is a perspective view of the rear of the machine, also with thehousings removed;

FIGJS is a front view of the machine with the housings removed;

FIG. 6 is a top view thereof, also with the housings removed;

FIG. 7 is a detail sectional view through FIG. 5 on the plane of theline 77;

FIG. 8 is a diagrammatic view illustrating in exaggerated manner theoscillation imparted to the bearing unit supporting the rotary brush;and

FIG. 9 is a perspective view of the nozzles and manifolds by which wateror other liquid can be supplied to the zone of action.

Referring to the drawings, it will be-seen that the machine can beconsidered as having a front section 5 and a rear section 6, separatedby a vertical wall 7 that forms part of a main frame 8. The frontsection constitutes the work performing zone through which the parts orwork to be acted upon are carried by an endless conveyor belt 9 to havetheir top surfaces subjected to the action of a rotary brush 10. Therear section 6 contains the drive mechanism for the brush and theconveyor, and other related mechanism to be described.

The main frame 8, which is conveniently formed as a weldment, comprisesa flat bottom 11, the vertical wall 7 and another vertical wall 12 thatis joined to the rear face of the wall 7 and projects at right anglestherefrom. Both vertical walls are fixed to and rise perpendicularlyfrom the bottom 11.

The endless conveyor belt 9 constitutes part of a work supporting unitdesignated generally by the nu-- to be appropriately tightened. Theother roller 19 is power driven and, for this purpose, has a shaftextension 19' that projects rearwardly beyond the wall.7.

Inasmuch as the elevation of the top surface of work on the work supportwith respect to the rotary brush and, more particularly, the undersideof the brush with which the work is to be engaged-depends upon thethickness of the work, it is essential that there be relative adjustmentbetween the work support and the brush. Also, any change in the diameterof the brush, whether the result of wear or replacement with a brush ofdifferent diameter, must be accommodated. To enable this neededadjustment, the work supporting unit 13 is vertically adjustably mountedon the wall 7. For this purpose an upright frame 22 is secured to therear rail of the horizontal box-like structureof the work support, andslidably connected with the side edges of the wall 7. Up and downadjustment of the work support is effected by a lead screw 24 rotatably,but not longitudinally movably mounted in a bearing 25 at the top of themain frame, and threaded in a nut 27 fixed to the frame 22. A hand wheel26 at the upper end of the lead screw conveniently enables rotation tobe imparted to the screw.

Where the work being handled by the machine is relatively thin sheetmaterial-as, for instance, printed circuit boards-it is important thatthe work be held down flat against the conveyor. This is the purpose ofa pair of hold-down rolls 30. The hold-down rolls are freely rotatablyjournaled in bearings 31 at the outer ends of arms 32 that are pivotallymounted at the underside of brackets 33. The brackets project forwardlyover the conveyor from another frame 35 whichlike the frame 22isvertically slidably mounted on the wall 7. Leaf springs 36 at theunderside of the brackets 33 impart a downward bias upon the arms 32 andhence onto the hold-down rolls.

Obviously, of course, the elevation of the hold-down rolls above thework support must accommodate the thickness of the work being handled,and to adjust that elevation an adjusting screw 38 reacts between theframes 22 and 35. This screw has threaded engagement with a nut 39 fixedto the frame 35 and has an unthreaded upper end portion which is freelyrotatably, but non-longitudinally movably journaled in a bearing40-fixed to the frame 22. A knob 41 on the unthreaded end portion of thescrew provides for the application of torque thereto. Thus, by turningthe knob, the elevation of the hold-down rolls above the endlessconveyor may be adjusted, from a miniumu-which may be zero-to a maximumwhich, in an actual commercial embodiment of the invention, is 2%inches.

Since it is also important that the work be firmly held against theconveyor belt regardless of the dimensions of the work, the hold-downrolls are adjustable towards and from one another. For this purpose, thebrackets 33 from which the rolls are supported have horizontallyslidable connections with the frame 35. These connections comprisehorizontal guideways 41 on the frame 35 in which mounting flanges 42 onthe brackets 33 ride, and clamping bolts 43 to clamp these flanges tothe guidewaysthe bolts passing through elongated slots in the flangesand being threaded into tapped holes in the guideways'.

The drive roll 19 of the endless belt conveyor has its front end freelyrotatably journaled in a bearing 45 that is mounted on the front rail 14and, at its rear end, the shaft extension 19' which is of reduceddiameterconstitutes or is joined to the output shaft of a gear reductionunit 46 that is mounted on the frame 22 rearwardly of the vertical wall7. A pulley 47 on the input shaft of the gear reduction unit providesfor the application of power to the conveyor belt, as will be laterdescribed. For the moment, it should be noted that the gear reductionunit, being fixed to the frame 22, moves up and down with the worksupporting unit as its elevation is adjusted.

The brush 10, which may be of any type depending upon the nature of thework to be performed, is detachably mounted on a spindle 48 thatprojects forwardly of the vertical main frame wall 7 at a fixedelevation. The spindle has its rear end portion journaled in bearingsfixed in a bearing block 49; but held against axialdisplacement withrespect thereto. The bearing block is supported from the wall 7 by apair of identical leaf springs 50. The free end portions of the leafsprings are clamped to but spaced somewhat from the axially oppositeends of the bearing block, and their anchored ends are similarly clampedto brackets 51 fixed to the wall 7 at opposite side thereof. Theanchored ends of the leaf springs are horizontally adjacent to onevertical edge of a square opening 52 in the wall 7 and the free ends'ofthe leaf springs terminate short of the opposite edge of the opening.The leaf springs thus straddle the wall 7 and the bearing block passesthrough the opening 52.

It should be noted that the clamps 53 by which the leaf springsare'anchored to the brackets 51 and to the bearing block, are verticallyoriented. It follows, there fore, that the motion of the bearing block,and hence the spindle, which results from flexure of the leaf springs,is constrained to a horizontal plane. The leaf springs thus provide avery practical and simple way of mounting the spindle and a brushthereon for axial oscillation without affecting the elevation of thebrush.

The desired axial oscillation of the spindle is produced by an eccentric54 that is connected with the bearing block by a connecting rod 55. Theeccentric is fixed to the upper end of a vertical shaft that protrudesfrom a gear box 56 mounted on the wall 12 of the main frame. Rotation isimparted to the eccentric through appropriate gearing in the gear box56, and to provide for the connection of this gearing with a powersource, a pulley 57 is fixed to its input shaft.

A single motor 58 which is mounted on the wall 12 of the main frame,provides the power to drive the brush spindle, the eccentric thatproduces the oscillation of the brush and the belt conveyor. To drivethe eccentric and the belt conveyor the shaft of the motor has a pulley59 which is drivingly connected by a belt 60 with the pulley 47 of thegear reduction unit 46 and the pulley 57 which provides an input for thedrive of the eccentric. Since the center-to-center distance between thepulley 47 and the other pulleys over which the belt 60 is trained isvariable because of the adjustability of the work supporting unit, aspring loaded belt tightener 61' is provided, the tightener beingmounted on a bracket 62 fixed to the back of the main frame wall 7.

Another belt 63 and two paired large and small driv-' ing and drivenpulleys on the motor shaft and on the spindle drivingly connect thebrush spindle with the motor, to drive the latter at either of twospeeds. The belt 63 is tightened by adjustment of the position of themotor on the wall 11, and since the belt need not be severely tensioned,it can be shifted from one pair of As seen in FIGS. 1 and 2, the machineis enclosed within a housing which consists of a rear section 70 and afront section 71. The rear section, which is partially formed by themain frame, houses those parts of the machine that should be protectedfrom the zone of action in which the work is acted upon by the brush.Hence, the drive motor and the drive transmission connecting it with thespindle, the driven roll of the belt conveyor and the eccentric, arelocated in the rear section. I

The front section of the housing is mounted on the frame 22 whichcarries the work supporting unit, and hence is raised and lowered withit. It consists of a pan 72 beneath the conveyor and a hood 73 over thebrush. The rear wall 74 of the pan is clamped between the rail and theadjacent portion of the frame 22, and the hood has its side and topwalls bolted to the frame 22. A door 75 in the front wall of the hoodaffords access to the brush to enable its removal from the spindle whenreplacement is desired. To facilitate detachment and reattachment ofbrushes, a knurled nut 76 threaded on the spindle coacts with a fixedflange to clamp the brush to the spindle.

When the machine is operated dry, the hood interior may be connectedwith a dust collector (not shown) through an exhaust port 77; and, whenoperated wet, a drain 78 in the bottom of the pan carries off the liquidemployed in the operation. 7

For wet operation, each of the brackets 33 on which the hold-down rollsare mounted has a pair of nozzles 80 mounted thereon and arranged todischarge towards the underside of the brush. The nozzles are secured inmanifolds 81 which are bolted to the brackets 33 and connected by hoseswith an inlet port 82 in one wall of the hood.

Those skilled in the art will appreciate that the invention can beembodied in forms other than as herein disclosed for purposes ofillustration.

The invention is defined by the following claims.

We claim: I i

l. A buffing and burnishing machine, wherein work fed through themachine is engaged by the peripheral surface of a rapidly rotatingbrush, characterized by an axially oscillatable mounting for the brushcomprising:

A. a bearing block having bearing means therein;

B. a spindle journaled in said bearing means but restrained againstaxial displacement with respect thereto, said spindle projecting fromthe bearing block;

C. a pair of leaf springs, each having one end portion thereof anchoredto part of the machine frame and its other end portion fixed to axiallyspaced surfaces ofthe bearing block, said leaf springs being disposed inflatwise spaced overlying relationship, and by their anchorage beingconstrained to flexure in a plane containing the spindle axis;

D. means detachably mountingthe brush on the spindle; and

E. power driven oscillating means connected with the bearing block toimpart axial reciprocation to it and thereby also axially oscillate thebrush.

2. The buffing and burnishing machine of claim 1, further characterizedby a power driven belt drive for the spindle to impart rotation to thespindle without interferring with its axial oscillation.

3. A buffing and deburring machine having:

1. a main frame including an upright supporting member with oppositesides;

2. a rotary brush spindle;

3. bearing means in which the brush spindle is freely rotatably but notaxially movably journaled;

4. means mounting the bearing means on said upright supporting memberwith its axis horizontal and, with said brush spindle projecting fromone side of said supporting member;

5. a rotary brush mounted on the spindle at said side of the uprightsupporting member;

6. power drive means at the opposite side of said upright supportingmember connected with the spindle to drive the same;

7. a work support at said first named side of said vertical uprightsupporting member and beneath the brush spindle, to be subjacent thebrush on the spindle so that work on the work support can be broughtinto engagement with the brush;

said machine being characterized in that the mounting means for thebearing means comprises:

A. a pair of leaf springs, each having a fixed end portion anchored tosaid upright supporting member and a free end portion constrained tomove in a horizontal plane towards and from said upright supportingmember as said leaf springs are flexed; and

B. means securing the free end portions of the leaf springs to axiallyspaced portions of the bearing means;

and wherein said power driven means includes reciprocation producingmeans connected with the bearing means and with the free ends of theleaf springs, to flex the leaf springs and axially reciprocate thebearing means.

4. The buffing and deburring machine of claim 3, further characterizedby:

A. hold-down means by which work on the work support is held thereon;

B. common mounting means for the work support and the hold-down meansvertically adjustably mounted on said upright supporting member; and

C. means for adjusting the elevation of said common mounting means sothat regardless of the diameter of the rotary brush and the thickness ofthe work, proper engagement between the brush and the top surface of thework can be assured.

5, The buffing and deburring machine of claim 4, wherein said leafsprings are at opposite sides of said upright supporting member, and thebearing means passes through an opening in said upright supportingmember.

6. The buffing and deburring machine of claim 5, wherein saidreciprocation producing means of the power driven means comprises aneccentric rotatably mounted on said upright supporting member at thesame side thereof as said power driven means, a connecting rodconnecting the eccentric with the bearing means and'the free ends of theleaf springs, and a driving connection between said power driven meansand the eccentric.

7. A buffing and deburring machine, comprising:

A. a main frame having a vertical supporting wall with front and backsides;

B. a rotary brush spindle having a front end portion and a rear endportion;

C. bearing means mounted on said vertical supporting wall and in whichthe rear end portion of the I brush spindle is journalled with its frontend portion protruding forwardly from the front side of said supportingwall;

D. a rotary brush detachably mounted on the front end portion of thespindle;

E. drive means connected with the rear end portion of the spindle toimpart rotation to the brush;

F. a frame vertically slidably mounted on said supporting wall;

G. a horizontal work support carried by said frame and projectingforwardly from the front side of said vertical wall beneath the rotarybrush; and

H. work hold-down means vertically adjustably mounted on said frameabove the work support, to hold work down on the work support as it isacted upon by the rotary brush, the adjustability of the work hold-downmeans on said frame enabling the maintenance of the correct hold-downpressure on the work regardless of its thicknesses, and theadjustability of said frame on the vertical supporting wall adapting themachine to operation with different diameter brushes without affectingthe pressure with which the work is held down on the work support.

8. The buffing and deburring machine of claim 7, wherein said worksupport comprises an endless belt having a top work carrying stretch andtrained about parallel spaced apart rollers journalled in bearings fixedwith respect to said frame, and a flat deck fixed with respect to saidframe and upon which the top work carrying stretch of the belt rides;and wherein said drive means is mounted on the main frame behind theback side of said vertical supporting wall and is drivingly connectedwith one of said rollers as well as with the brush spindle.

'9. The buffing and deburring machine of claim 8, wherein said workhold-down means comprises: a pair of idler rollers at opposite sides ofthe rotary brush; and biasing means acting on said rollers to urge themdownwardly towards the top work carrying stretch of the endless belt.

1. A buffing and burnishing machine, wherein work fed through themachine is engaged by the peripheral surface of a rapidly rotatingbrush, characterized by an axially oscillatable mounting for the brushcomprising: A. a bearing block having bearing means therein; B. aspindle journaled in said bearing means but restrained against axialdisplacement with respect thereto, said spindle projecting from thebearing block; C. a pair of leaf springs, each having one end portionthereof anchored to part of the machine frame and its other end portionfixed to axially spaced surfaces of the bearing block, said leaf springsbeing disposed in flatwise spaced overlying relationship, and by theiranchorage being constrained to flexure in a plane containing the spindleaxis; D. means detachably mounting the brush on the spindle; and E.power driven oscillating means connected with the bearing block toimpart axial reciprocation to it and thereby also axially oscillate thebrush.
 2. The buffing and burnishing machine of claim 1, furthercharacterized by a power driven belt drive for the spindle to impartrotation to the spindle without interferring with its axial oscillation.2. a rotary brush spindle;
 3. A buffing and deburring machine having: 3.bearing means in which the brush spindle is freely rotatably but notaxially movably journaled;
 4. means mounting the bearing means on saidupright supporting member with its axis horizontal and, with said brushspindle projecting from one side of said supporting member;
 4. Thebuffing and deburring machine of claim 3, further characterized by: A.hold-down means by which work on the work support is held thereon; B.common mounting means for the work support and the hold-down meansvertically adjustably mounted on said upright supporting member; and C.means for adjusting the elevation of said common mounting means so thatregardless of the diameter of the rotary brush and the thickness of thework, proper engagement between the brush and the top surface of thework can be assured.
 5. The buffing and deburring machine of claim 4,wherein said leaf springs are at opposite sides of said uprightsupporting member, and the bearing means passes through an opening insaid upright supporting member.
 5. a rotary brush mounted on the spindleat said side of the upright supporting member;
 6. power drive means atthe opposite side of said upright supporting member connected with thespindle to drive the same;
 6. The buffing and deburring machine of claim5, wherein said reciprocation producing means of the power driven meanscomprises an eccentric rotatably mounted on said upright supportingmember at the same side thereof as said power driven means, a connectingrod connecting the eccentric with the bearing means and the free ends ofthe leaf springs, and a driving connection between said power drivenmeans and the eccentric.
 7. A buffing and deburring machine, comprising:A. a main frame having a vertical supporting wall with front and backsides; B. a rotary brush spindle having a front end portion and a rearend portion; C. bearing means mounted on said vertical supporting walland in which the rear end portion of the brush spindle is journalledwith its front end portion protruding forwardly from the front side ofsaid supporting wall; D. a rotary brush detachably mounted on the frontend portion of the spindle; E. drive means connected with the rear endportion of the spindle to impart rotation to the brush; F. a framevertically slidably mounted on said supporting wall; G. a horizontalwork support carried by said frame and projecting forwardly from thefront side of said vertical wall beneath the rotary brush; and H. workhold-down means vertically adjustably mounted on said frame above thework support, to hold work down on the work support as it is acted uponby the rotary brush, the adjustability of the work hold-down means onsaid frame enabling the maintenance of the correct hold-down pressure onthe work regardless of its thicknesses, and the adjustability of saidframe on the vertical supporting wall adapting the machine to operationwith different diameter brushes without affecting the pressure withwhich the work is held down on the work support.
 7. a work support atsaid first named side of said vertical upright supporting member andbeneath the brush spindle, to be subjacent the brush on the spindle sothat work on the work support can be brought into engagement with thebrush; said machine being characterized in that the mounting means forthe bearing means comprises: A. a pair of leaf springs, each having afixed end portion anchored to said upright supporting member and a freeend portion constrained to move in a horizontal plane towards and fromsaid upright supporting member as said leaf springs are flexed; and B.means securing the free end portions of the leaf springs to axiallyspaced portions of the bearing means; and wherein said power drivenmeans includes reciprocation producing means connected with the bearingmeans and with the free ends of the leaf springs, to flex the leafsprings and axially reciprocate the bearing means.
 8. The buffing anddeburring machine of claim 7, wherein said work support comprises anendless belt having a top work carrying stretch and trained aboutparallel spaced apart rollers journalled in bearings fixed with respectto said frame, and a flat deck fixed with respect to said frame and uponwhich the top work carrying stretch of the belt rides; and wherein saiddrive means is mounted on the main frame behind the back side of saidvertical supporting wall and is drivingly connected with one of saidrollers as well as with the brush spindle.
 9. The buffing and deburringmachine of claim 8, wherein said work hold-down means comprises: a pairof idler rollers at opposite sides of the rotary brush; and biasingmeans acting on said rollers to urge them downwardly towards the topwork carrying stretch of the endless belt.